Fin field effect transistors including complimentarily stressed channels

Abstract

A stressed single crystalline epitaxial semiconductor layer having a first type stress is formed on a single crystalline substrate layer. First and second semiconductor fins are formed by patterning the stressed single crystalline epitaxial semiconductor layer. A center portion of each first semiconductor fin is undercut to form a recessed region, while the bottom surface of each second semiconductor fin maintains epitaxial registry with the single crystalline substrate layer. The center portion of each first semiconductor fin is under a second type of stress, which is the opposite of the first type of stress. A first field effect transistor formed on the first semiconductor fins can include first channels under the second type of stress along direction of current flow, and a second field effect transistor formed on the second semiconductor fins can include second channels under the first type of stress along the direction of current flow.

Dependencies are inferred from the claim text.